1. Technical Field
The invention relates to a guide apparatus, and in particular, to an apparatus for guiding strip material to a tire-building drum. More particularly, the invention relates to a guide apparatus for maintaining a tread strip centered as it moves through the apparatus for accurate placement and alignment of the tread strip on an adjacent tire-building drum.
2. Background of the Invention
Apparatus, as is that of the present invention, is generally referred to in the tire-building art as a "server" or "guide", and typically includes a flat table or plate which is positioned in operative position with a tire-building drum. On the upper surface of the guide plate or table are transversely movable guide members or fences selectively adjustable to various predetermined spacings established by the width of the particular flat tire components being applied to the drum.
Heretofore, these fences or guide members have been simultaneously moved transversely to the surface of the guide plate by various mechanisms. For example, in U.S. Pat. No. 1,711,074, a shaft and drive sprocket has been provided with detente fingers extending radially of the shaft and selectively engaged in a spring detente fixed to a support plate. Manual rotation of the sprocket shaft would move from one detente position to the next, thus establishing a desired number of preselected locations for the spaced guide members.
U.S. Pat. No. 3,170,829 shows another guide apparatus for a tire-building machine which uses a chain drive linkage for setting the spacing between the guide rails or fences. Coil springs are used to bias the guides away from each other and toward an outward position out of engagement with the strip material being conveyed therebetween.
U.S. Pat. No. 3,269,627 shows another type of guide mechanism for hot strip material in which the two fences and guides are moved by a piston cylinder assembly and a rotatable shaft for adjusting the position between the two guides.
U.S. Pat. No. 4,750,660 discloses another guide apparatus for sheet material in which the guide rails are positioned by means of a rotatable threaded shaft and guide blocks, and a positioning cylinder for setting the desired spacing between the rails.
U.S. Pat. No. 4,961,831 shows a guide mechanism for sheet material for a tire-building drum in which the spacing between the guide members is achieved by a drive belt and drive motor.
Although these prior guide devices provide for the accurate setting of the guide fences or rails, they do not provide for the automatic simultaneous adjustment of the guide rails in order to compensate for increased or decreased strip widths which does occur in many strip components while being fed to a tire-building drum. This can result in the moving strip being moved off-center, and, therefore, inaccurately delivered to the tire-building drum. As the complexity of the tire structure has increased, the necessity for extreme accuracy in positioning the guide members or guide rails for delivery of the flat strip component has become more critical, especially when used with automated tire-making equipment.
Therefore, the need exists for a guide apparatus to be used primarily for a tire building drum which will automatically compensate for variations in strip width as it moves toward the tire-building drum and through the server to maintain the strip centered in the server to provide accurate delivery to the tire-building drum.